Portion of a keyboard



FIG. 1 is a front perspective view of a keyboard showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is an enlarged perspective view of the claimed region of FIGS. 1 and 2 showing the claimed key configuration; and,

FIG. 4 is a top view thereof.

The broken line showing of the remainder of the keyboard is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a keyboard, as shown and described. 